Restructuring - Summary of Net Pretax Charges Incurred by Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Net pretax benefits (charges), incurred by segment [Line items]
Restructuring, net	$ (6)	$ (20)	$ (51)	$ (40)
Operating Segments | Global Business Solutions
Net pretax benefits (charges), incurred by segment [Line items]
Restructuring, net	(2)	(9)	(7)	(14)
Operating Segments | Global Financial Solutions
Net pretax benefits (charges), incurred by segment [Line items]
Restructuring, net	0	(5)	(2)	(9)
Operating Segments | Network & Security Solutions
Net pretax benefits (charges), incurred by segment [Line items]
Restructuring, net	0	(1)	(2)	(1)
Corporate
Net pretax benefits (charges), incurred by segment [Line items]
Restructuring, net	$ (4)	$ (5)	$ (40)	$ (16)